Make the update editor install a 'not-present' node when deleting a switched
subpath as part of the update. This fixes issue #4295, by making missing nodes
reappear on future updates.

* subversion/libsvn_wc/update_editor.c
  (delete_entry): Detect when deleting a node that is switched vs its parent,
    and in this specific case install a not present node so future updates
    will restore possible missing children.

* subversion/tests/cmdline/update_tests.py
  (update_removes_switched): Extend test to also cover issue #4295.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1435722 13f79535-47bb-0310-9956-ffa450edef68